• Applied Microscopy
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• v.22 no.2
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• pp.118-126
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• 1992

The pathway and time course of fucose-containing glycoprotein synthesis and intracellular translocation in osteoclasts of the mice maxillary alveolar bone were investigated by electron microscopic radioautography. Male Balb-C mice weighing 17gm were anesthetized with Nembutal and injected via the external jugular vein with 2.5 mCi of $L-[6-^{3}H]-fucose$ (specific activity 16.8 mCi/mmol) in 0.1 ml of sterile saline solution. At 5, 10, 20, 35 minutes and 8 hours after administration of the $^{3}H-fucose$, animals were killed by intracardiac perfusion of 30ml of 2% glutaraldehyde in a modified Tyroid solution, pH 7.4. The maxillae were then removed and further fixed in Karnovsky fixative for an additional 3-4 hours. After rinsing in 0.1M cacodylate buffer for 10 minutes, the maxillae were demineralized for 2 weeks at $4^{\circ}C$ in ethylene diamine tetra acetate containing 2% glutaraldehyde. The first interdental areas were mesiodistally sectioned into slices of 1mm thickness and postfixed in osmium tetroxide. Tissues were then dehydrated and embedded in Poly Bed. To prepare electron microscopic radioautography, the dipping method of Kopriwa (1973) was employed. Thin sections were coated with a crystalline monolayer of ILford $L_4$ photographic emulsion. After exposure for 4 months at $4^{\circ}C$, the sections were developed Kodak Microdol-X and Phenidon (for compact grains), fixed in 30% sodium thiosulfate, stained with uranyl acetate and lead citrate and examined in the electron microscope (JEOL 1200 EX). At 5, 10 and 20 minutes after injection, $^{3}H-fucose$ was concentrated in Golgi cisternae of the osteoblasts. By 35 minutes the labels were observed over small vesicles in the suprannclear area of osteoclasts. At 8 hours, numerous silver grains were located on the ruffled border and cell membrane of osteoclasts. These results indicate that fucose molecules are added in the Golgi apparatus and small vesicles appear to be responsible for translocation of the glycoproteins to the marginal portion of osteoblasts. The glycoproteins are distributed on the osteoclast cell surface and especially over the ruffled border.

• KSBB Journal
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• v.9 no.3
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• pp.287-293
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• 1994

A bacterium isolated from waste coal mine water around Hawsun had an ability for the degradation of hydrogen sulfide. The isolate was identified as Thiobacillus sp. IW. on the basis of its morphological, physiological and chemotaxonomical characteristics. The optimum pH and temperature were 7 and $30^{\circ}C$, respectively. Growth occurred in a pH range of 3 to 9. Due to the sulfate accumulated in liquid medium, the pH decreased. As a consequence the cell growth was inhibited. Potasium nitrate and glutamic acid were utilized as a nitrogen source but urea and ammonium chloride not consumed. Denitrification occurred in a basal medium containing the glucose but did not in a basal medium containing the malate. The maximum specific growth rate of cell was 0.78h-1 and generation time was 0.9 hour. The cell productivity was 6.25mg/1$.$h and the isolate grew logarithmically up to 18 hour. These results indicate that the isolate can be a suitable bacterium responsible for degradation of hydrogen sulfide as malodorous compounds.

• The Journal of the Korean dental association
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• v.52 no.2
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• pp.96-104
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• 2014

The aim of this study was to investigate the frequency of positive patch test reaction to dental materials in patients with oral mucosal diseases. Epicutaneous patch test was performed in 110 patients with oral mucosal diseases; 41 patients with oral lichen planus(OLP), 44 patients with burning mouth syndrome(BMS), 25 patients with other oral mucosal diseases including recurrent aphthous ulcer and mucous membrane pemphigoid. The obtained results were as follows: Oral gold restorations were most common in patents with oral mucosal diseases and porcelain fused metal crown, implant appeared in the order. 33 of 110 patients did not appear skin reactions (negative, 30%) and 77 patients (positive, 70%) had skin reactions including redness, rash, blisters. Dental materials causing positive reaction to patch test were mainly as gold-sodium-thiosulfate (26.7%), nickel sulfate(Ni) (22.7%), cobalt chloride(Co) (14.7%), palladium chloride(Pd) (11.9%), potassium dichromate (10.7%) in order, respectively. In conclusion, old metal restorations could be the cause of oral mucosal diseases and epicutaneous patch test could be used as a tool to improve the oral conditions.

• Korean Journal of Environmental Biology
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• v.34 no.2
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• pp.116-123
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• 2016

The ecotoxicity tests for metal plating wastewater were conducted using Daphnia magna (D. magna) and Euglena agilis (E. agilis). Evaluation for sources of toxicity was performed by 1) Correlation analysis between the concentration of individual metals in the metal plating wastewater and the toxic effects on D. magna, 2) Toxicant identification evaluation methods including graduated pH method, EDTA procedure and sodium thiosulfate procedure, 3) Comparison of toxic effect value ($EC_{50}$ or $LC_{50}$) of individual metal on D. magna and it's concentration in the metal plating wastewater. To evaluate the possibility of E. agilis, a Korean domestic organism, as a test model organism for metal plating waste water, E. agilis toxicity test was also assessed using on-line euglena ecotoxicity system (E-Tox system). Based on toxicant characterization test using D. magna, it was expected that SS, oxidants and heavy metals are responsible for toxicity of metal plating waste water. Especially Cu, Hg, and Ag were the major cationic metals that caused toxicity. E. agilis is less sensitive than D. magna based on the $EC_{50}$ value however it shows prompt response to toxic test substances. E. agilis shows even a significant effect on the cell swimming velocity within 2 min to toxic metal plating wastewater. Our study demonstrates that E. agilis test can be a putative ecotoxicity test for assessing the quality of metal plating waste water.

• Resources Recycling
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• v.26 no.1
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• pp.51-58
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• 2017

The present study to develop a process for extracting nitric acid and gold from aqua regia leach solution using TBP(tributyl phosphate) was conducted. The pure aqua regia was used to investigate the extractive behavior of nitric acid depending on the concentration of extractant, concentration ratio of nitric and hydrochloric acid. The extraction rate of nitric acid and gold from the gold bearing aqua regia was also examined. The theoretical extraction number was verified by counter current using the number of operations and the phase ratio obtained from McCabe-Thiele diagram. Stripping experiments were carried out for continuous recovery of nitric acid and gold in loaded organic. Considering the effect of extraction acid and gold, the simulation showed that greater than 99.9% extraction of $103.0mg{\cdot}L^{-1}$ gold and 98.0% of $151.2g{\cdot}L^{-1}$ nitric acid could be attained in a two and three-stage counter-current extraction at an O/A phase ratio of 1:0.85. Distilled water and sodium thiosulfate were used as the nitric acid and gold stripping solution. The stripping rates were 99.5% and 92.0%, respectively. The study revealed that the recovery of nitric acid and gold from gold bearing aqua regia was a plausible approach through simultaneous extraction and continuous stripping of nitric acid and gold.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.252-260
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• 2009

Rice is the most important cereal crop not only in supplying the basic staple food for more than half of the world's population but also as a model plant for functional genomic studies of monocotyledons. Although rice transformation method using A. tumefaciens has already been widely used to generate transgenic plants, the transformation rate is still low in most Korean elite cultivars. We made several modifications of the standard protocol especially in the co-cultivation step to improve the efficiency of the rice transformation. The co-culture medium was modified by the addition of three antioxidant compounds (10.5 mg/L L-cysteine, 1 mM sodium thiosulfate, 1 mM dithiothreitol) and of Agrobacterium growth-inhibiting agent (5 mg/L silver nitrate). Co-cultivation temperature ($23.5^{\circ}C$ for 1 day, $26.5^{\circ}C$ for 6 days) and duration (7 days) were also changed. The plasmid of pMJC-GB-GUS carrying the GUS reporter gene and the bar gene as the selectable marker was used to evaluate the efficiency of the transformation. After co-cultivation, a high level of GUS gene expression was observed in calli treated with the modified method. It is likely that those newly added compounds helped to minimize the damage due to oxidative bursts during plant cell-Agrobacterium interaction and to prevent necrosis of rice cells. And the transformation rate under the modified method was also remarkably increased approximately 8-fold in Heungnambyeo and 2-fold in Ilmibyeo as compared to the corresponding standard method. Furthermore, we could produce the transgenic plants stably from Ilpumbyeo which is a high-quality rice but its transformation rate is extremely low. Transformation and the copy number of transgenes were confirmed by PCR, bar strip and Southern blot analysis. The improved method would attribute reducing the effort and the time required to produce a large number of transgenic rice plants.

• The Korean Journal of Nuclear Medicine
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• v.32 no.3
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• pp.298-304
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• 1998

Purpose: We evaluated the usefulness of Re-188 sulfur colloid for radiation synovectomy and therapy of intraperitoneal metastasis. Materials and Methods: We investigated the labeling efficiency of Re-188 sulfur colloid on various conditions. The stability of Re-188 sulfur colloid was observed at room temperature for 24 h and in human serum and synovial fluid for 72 h. The particle size distribution of Re-188 sulfur colloid was measured by filtering with various pore size filters. Animal experiment was performed in mice and rabbits. Results: The labeling efficiency of Re-188 sulfur colloid was $64.5{\pm}5.8%$ (n=5) at the conditions of sodium thiosulfate 40 mg, EDTA $Na_2.2H_2O$ 0.8 mg, $KReO_4$ 0.8 mg at pH 1. After purification, the radiochemical purity was higher than 99%. The stability of Re-188 sulfur colloid was high (>99%) at room temperature for 24 h and in human serum and synovial fluid for 72 h. The particle size distribution of Re-188 sulfur colloid was 0.3% ($<1{\mu}m$), 11.2% ($1{\sim}5{\mu}m$), 25.8% ($5{\sim}10{\mu}m$) and 52.8% ($>10{\mu}m$). In mice, 1 h postinjection of Re-188 sulfur colloid into tail vein, uptakes in lung, liver and muscle were $37.30{\pm}5.36$, $32.33{\pm}1.79$, $6.60{\pm}0.02%$ ID/organ respectively. After i.p. injection in mice, the uptakes of extraperitonial organs of Re-188 sulfur colloid at 1 and 24 h were $0.1{\pm}0.1$, $0.4{\pm}0.1%$ ID/organ, and the excretions through urine and feces (${\sim}70 h$) were low ($2.68{\pm}0.80$, $0.95{\pm}0.17%$). When Re-188 sulfur colloid was injected to synovial space of rabbit, the uptake in other organs except knee was very low. Conclusion: Re-188 sulfur colloid showed high labeling efficiency, stability and potency for clinical use.